Hepatitis C and risk of lymphoma: results of the European multicenter case-control study EPILYMPH.

BACKGROUND & AIMS: Increasing evidence points toward a role of hepatitis C virus (HCV) infection in the etiology of malignant lymphomas. However, previous epidemiologic studies were limited in size to establish an association between HCV infection and specific lymphoma subtypes. We performed a large, multicenter, case-control study to address this question.

METHODS

The study comprised 5 European countries and included newly diagnosed cases of any lymphoid malignancy recruited between 1998 and 2004. Controls were matched to cases by 5-year age group, sex, and study center. In-person interviews were conducted to collect data on demographic, medical, and family history as well as environmental exposures. Serum samples of 1807 cases and 1788 controls (excluding human immunodeficiency virus-positive and organ-transplantation subjects) were screened for HCV infection using an enzyme immunoassay. Positive as well as randomly selected negative samples were subjected to HCV RNA detection and HCV genotyping.

RESULTS

HCV infection was detected in 53 (2.9%) lymphoma cases and in 41 (2.3%) control subjects (odds ratio [OR], 1.42; 95% confidence interval [CI]: 0.93-2.15). Restricted to individuals who tested positive for HCV-RNA (indicating persistent infection and active viral replication), the OR was 1.82 (95% CI: 1.13-2.91). In subtype-specific analyses, HCV prevalence was associated with diffuse large B-cell lymphoma (OR, 2.19; 95% CI: 1.23-3.91) but not with chronic lymphocytic leukemia or follicular, Hodgkin's, or T-cell lymphoma. The sample size was not sufficient to derive any conclusions for rare lymphoma entities such as splenic marginal zone lymphoma.

CONCLUSIONS

These results support a model that chronic HCV replication contributes to lymphomagenesis and establish a specific role of HCV infection in the pathogenesis of diffuse large B-cell lymphoma.